CVE-2026-23388
Description
A flaw was found in the Linux kernel's Squashfs component. A local attacker could craft a malicious Squashfs image with a corrupted index look-up table, leading to a negative metadata block offset. This negative offset causes an out-of-bounds access when processing the image, resulting in a general protection fault and a system crash, effectively causing a Denial of Service (DoS).
Statement
A kernel crash can occur in Squashfs metadata handling because a corrupted index lookup table can produce a negative metadata block offset. The negative offset is later used by squashfs_read_metadata and can lead to an out of bounds access in squashfs_copy_data which triggers a general protection fault. For the CVSS the PR:L because an attacker typically needs the ability to provide or mount a crafted Squashfs image or otherwise influence the filesystem contents.
Mitigation
To mitigate this issue, prevent module squashfs from being loaded. Please see https://access.redhat.com/solutions/41278 for how to blacklist a kernel module to prevent it from loading automatically.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 6.6 | 7.1 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | Low | High | N/A |
| Integrity Impact | Low | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Understanding the Weakness (CWE)
Other
Technical Impact: Varies by Context
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